Climate change is latest threat to world's dwindling fish stocks

Washington, March 17 : A new report by the UN Environment Programme (UNEP) has suggested that climate change is emerging as the latest threat to the world's dwindling fish stocks.

The report suggests that at least three quarters of the globe's key fishing grounds may become seriously impacted by changes in circulation as a result of the ocean's natural pumping systems fading and falling.

These natural pumps, dotted at sites across the world including the Arctic and the Mediterranean, bring nutrients to fisheries and keep them healthy by flushing out wastes and pollution.

But, the impacts of rising emissions on the marine world are unlikely to end there.

Higher sea surface temperatures over the coming decades threaten to bleach and kill up to 80 per cent of the globe's coral reefs-major tourist attractions, natural sea defences and also nurseries for fish.

According to Christian Nellemann, who headed up the rapid response team that compiled the report, "We are already seeing evidence from a number of studies that increasing sea temperatures are causing changes in the distribution of marine life".

Meanwhile, there is growing concern that carbon dioxide emissions will increase the acidity of seas and oceans. This in turn may impact calcium and shell-forming marine life including corals but also tiny ones such as planktonic organisms at the base of the food chain.

"The worst concentration of cumulative impacts of climate change with existing pressures of over-harvest, bottom trawling, invasive species infestations, coastal development and pollution appear to be concentrated in 10-15 per cent of the oceans," said the report.

This 10-15 per cent of the oceans is far higher than had previously been supposed and is "concurrent with today's most important fishing grounds" including the estimated 7.5 per cent deemed to be the most economically valuable fishing areas of the world, it added.

According to Achim Steiner, UN Under-Secretary General and UNEP Executive Director, "Climate change threatens coastal infrastructure, food and water supplies and the health of people across the world."

"In Dead Water has uniquely mapped the impact of several damaging and persistent stresses on fisheries. It also lays on top of these the likely impacts of climate change from dramatic alternations in ocean circulation affecting perhaps a three quarter of key fishing grounds up to the emerging concern of ocean acidification," he added.